O o-dialkyl phosphorodithioate and phosphorothioate esters of oxazol-idine-2 4-dione derivatives as systemic insecticides

ABSTRACT

COMPOUNDS OF THE FORMULA   2,4-DI(O=),3-((R&#39;&#39;-O-)2-P(=Y)-S-CH(-R2)-),5-R3-OXAZOLIDINE   IN WHICH Y IS O OR S, R1 IS CH3 OR C2H5, R2 AND R3 ARE H OR CH3 AND INSECTICIDAL DISPERSIBLE CONCENTRATES CONTAINING 10-50% OF SAID COMPOUND AND 50-90% OF A DISPERSING AGENT HAVE SYSTEMIC INSECTICIDAL ACTIVITY AGAINST THE TWO-SPOTTED MITE.

United States Patent 0,0-DlALKYL PHOSPHORODITHIOATE AND PHOSPHOROTHIOATE ESTERS 0F OXAZOL- IDINE-2,4-DIONE DERIVATIVES AS SYS- TEMIC INSECTICIDES Joel D. Jamison, Westminster, Wilmington, DeL, assignor to Hercules Incorporated, Wilmington, Del. No Drawing. Filed Jan. 2, 1968, Ser. No. 694,813 Int. Cl. Atlln 9/36; C07f 9/16 US. Cl. 260-307 B 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to organosphosphorous compounds containing a 2,4-oxazolidinedione ring system, and to insecticidal compositions containing the same.

In accordance with this invention it has been found that compounds of the formula in which Y is O or S, \R is CH or C H R and R are individually H or CH are highly toxic by systemic action to the two-spotted mite.

The compounds of this invention are readily absorbed by plants through the root system and, in many cases, also through the foliage, and they are transported through the plant to the growing tips where the toxicity is exerted on insects which attack the plant.

LIH practicing the invention, the toxic compounds are placed in the locus of the roots for absorption through the roots, or on the foliage for absorption through the foliage. The toxic compounds are used in compositions in admixture with a granular solid carrier or a wettable powder or as an aqueius emulsion of the compound itself or of the compound dissolved in an organic solvent or adsorbed on a wettable powder. The composition of the toxic compound adsorbed on a granular solid is used when applied along with seeds at planting. The mixture of granular solid and seeds is then planted together. The toxic compound may also be applied to the seeds themselves as a wettable powder, as an aqueous emulsion, or as an organic solvent solution so that the toxic compound is placed in the locus of the roots by planting of the seeds. The toxic compounds can also be added to the soil after the plants to be protected have sprouted by directing an aqueous emulsion of the toxic compound with or without a solid carrier to the locus of the roots in the soil, and the toxic compound will be carried into the soil with rain or artificial watering.

3,632,598 Patented Jan. 4, 1972 The toxic compounds are alternatively applied to the foliage as an aqueous emulsion, with or without a solid carrier, when treatment is made when the plants are in the foliage stage of growth.

The methods of using systemic insecticides are well known in the art.

The compounds of this invention are made available commercially as dispersible concentrates of the toxic compound and a surface active dispersing agent. The dispersing agent is a solid inorganic dispersing agent which is itself finely divided or is a dispersible aggregate of finely divided particles, or the dispersing agent is an organic surface active agent. The inorganic surface active agents include talc, attapulgite, pyrophylite, diatomaceous earth, kaolin, aluminum and magnesium silicates, montmorillonite and other clays, fullers earth and their equivalents.

Suitable organic surface active agents are anionic cationic or non-ionic surface active agents. These include alkali metal (sodium or potassium) oleates and similar soaps, amine salts of long chain fatty acids (oleates), sulfonate animal and vegetable oils (fish oils and castor oil), sulfonated petroleum oils, sulfonated acyclic hydrocarbons; sodium salts of lignin sulfonic acids, sodium alkylnaphthalene sulfonates, sodium lauryl sulfonate, disodium monolauryl phosphates; sorbitol laurate, pentaerythritol monostearate, glycerol monostearate, polyethylene oxides; ethylene oxide condensates of stearic acid, stearyl alcohol, stearyl amine, rosin amine, dehydroabietyl amine, glycerol monolaurate and the like; lauryl amine salts, dehydroabietyl amine salts, lauryl pyridinium bromide, stearyltrimethylammonium bromide and cetyldimethylbenzylammonium chloride.

When the dispersing agent comprises an inorganic surface active agent an organic surface active agent is often used with it to produce a wettable powder.

When the dispersing agent comprises an organic surface active agent, an organic solvent is often included in an amount necessary to produce a homogeneous fluid solution which is readily pourable. The organic solvent is one which dissolves both the toxicant and the surface active agent. Such solvents include low molecular weight alcohols, acetone, methyl ethyl ketone, toluene, xylenes and petroleum distillates.

The toxicants are usually compounded in the form of water dispersible concentrates which contain 10-50% toxicant and 50-90% dispersing agents, wherein the dispersing agent comprises either 20100% organic surface active agent, and up to organic solvent in which the surface active agent is soluble or, in the case where the concentrate is a wettable powder, the dispersing agent is 50-100% of a solid inorganic surface active agent, and up to 50% organic surface active agent.

The emulsifiable concentrate is usually diluted with water to form an aqueous emulsion having a concentration in the range of 0.00055% toxicant, and this is sprayed on the locus of the roots or foliage of the plants to be protected.

The compounds of this invention are made by one of the following methods where N-CHzCHzOH CN CHZO c -OHzOlI lPCl CN-CllzCl N-'CHZ"SPY(OR1)Z R3(3HC o The preparation of the compounds of this invention is illustrated by the following examples:

EXAMPLE 1 A mixture of 17.2 g. of 2,4-oxazolidinedione, 6.0 g. paraformaldehyde and 0.1 g. Ba(OH) was melted and heated at 90 C. for one hour. The melt was taken into methylene chloride (100 ml.) and treated with 36 g. phosphorous pentacholride. The mixture was let stand overnight at 25 C. and the solvent removed. The residue was treated with cold water and recrystallized from isopropanol to give 16.3 g. of 3-chloromethyl-2,4-oxazolidinedione; M.P. 68-69 C., which analyzed 23.7% chlorine (theory: 22.7%).

A mixture of 7.5 g. 3-chloromethyl-2,4-oxazolidinedione and 9.6 g. of ammonium 0,0-dimethyl phosphorodithioate in 40 ml. of water was heated at 40-5 0 C. for 8 hours. The organic layer was taken up in benzene and washed with aqueous sodium bicarbonate and water and then dried. On removal of the solvent, there remained 12.2

g. 0,0-dimethyl S-(2,4-oxazolidinedione-3-yl) methyl phosphorodithioate as a colorless oil which analyzed 11.5% P. (11.4% P., theory).

EXAMPLE 2 Following the procedure of Example 1, 11.8 g. of ammonium O,O-diethyl pohsphorodithioate was reacted with 7.5 g. 3-chloromethyl-2,4-oxazolidinedione, and 14.4 g. 0, O-diethyl S-(2,4-oxazolidinedione-3-yl) methyl phosphorodithioate was recovered as a colorless oil which analyzed 9.8% P. (10.3% P., theory).

EXAMPLE 3 Following the procedure of Example 1, 12.3 g. of 3- chloromethyl-5-methyl-2,4-oxazolidinedione prepared in an analogous manner was reacted with 14.4 g. ammonium 0,0-dimethyl phosphorodithioate, and 17.4 g. 0,0-dimethyl S-(S-methyl-Z,4-oxazolidinedione-3-yl) methyl phosphorodithioate was recovered as an oil which analyzed 11.2% P. (10.9% P., theory).

EXAMPLE 4 Following the procedure of Example 1, 12.3 g. of 3- chloromethyl-5-methyl-2,4-oxazolidinedione prepared in 4 analogous manner was reacted with 17.6 g. of ammonium 0,0-diethyl phosphorodithioate and 18.8 g. O,'O-diethyl S (5-methyl-2,4-oxazolidinedione-3 -yl) methyl phosphorodithioate was obtained as a oil whicnh analyzed 9.9% P. (9.1% P., theory).

EXAMPLE 5 3-Vinyl-5-methyl-2,4-oxazolidinedior1e was prepared from 5-methyl-2,4-oxazolidionedione by the procedure for making 3-vinyl-2,4-oxazolidinedione in Example 9 hereinafter.

A solution of 11.5 g. of 0,0-dimethyl phosphorodithioic acid and 8.4 g. 3-vinyl-5-methyl-2,4-oxazolidinedione in 50 ml. benzene was heated at 50 C. for 3 hours, and the benzene was distilled off with final heating for 3 hours at C. The product was redissolved in benzene, washed with 5% aqueous sodium bicarbonate and water and dried. On removal of the benzene, there remainded 15.3 g. O ,O-dimethyl S-[1-(5-methy1-2,4-oxazolidinedione-3'-yl)ethylJphosphorodithioate which was an oil analyzing 11.2% P. (10.4% P., theory).

EXAMPLE 6 Following the procedure of Example 5, 13.5 g. 0,0-diethyl phosphorodithioic acid was reacted with 8.4 g. 3- vinyl-5-methyl-2,4-oxazolidinedione and 17.5 g. 0,0-diethyl S- 1- 5 -methyl-2,4'-oxazolidinedione-3 -yl) ethyl] phosphorodithioate which was an oil analyzing 9.9% P. (9.5% P., theory) was obtained.

EXAMPLE 7 A mixture of 20.2 g. of 2,4-oxazolidinedione, 6.6 g. of paraformaldehyde and 0.1 g. Ba(OH) was melted and heated at 90 C. for one hour. The melt was taken into ml. methylene chloride and 18.2 g. phosphorous tribromide added at 010 C. The mixture was let stand at 25 C. overnight, the methylene chloride solution decanted and the solvent removed. The residue was washed with water and recrystallized to give 16.7 g. of 3-bromomethyl- 2,4-oxazolidinedione; M.P. 63-64" C. An NMR spectrum was consistent with its structure.

A mixture of 15.0 g. 3-bromomethyl-2,4-oxazolidinedione and 13.0 g. ammonium 0,0-dimethyl phosphorothiate in 100 ml. acetonitrile was heated at 25 C. for 48 hours, and at 60 C. for 4 hours. The mixture was filtered, the acetonitrile was distilled oil, and the residue was dissolved in methylene chloride. The methylene chloride solution was filtered, and the filtrate was freed of solvent by heating under reduced pressure. The residue from this treatment was 15.3 g. 0,0-dimethyl S-(2,4-oxazolidinedione-3-yl) methyl phosphorothioate which analyzed 12.6% P. )12.2% P., theory).

EXAMPLE 8 A mixture of 15.0 g. 3-chloromethyl-2,4-oxazolidinedione and 20.4 g. ammonium 0,0-diethyl phosphorothioate in 100 ml. dimethyl sulfoxide was heated at 25 C. for 48 hours, and at 60 C. for 3 hours. The mixture was diluted with 100 ml. Water, and extracted with methylene chloride. The methylene chloride extract was dried and freed of solvent to obtain 18.3 g. O,'O-diethyl S-(2,4- oxazolidinedione-3-yl) methyl phosphorothioate which analyzed 11.1% P. (10.9% P., theory).

EXAMPLE 9 A mixture of 202 g. of 2,4-oxazolidinedione, 185 g. of ethylene carbonate and 1.0 g. of sodium bicarbonate was heated to 155-160 C. for three hours. The melt was cooled, dissolved in 500 ml. pyridine and treated with 220 g. of acetic anhydride. This mixture was heated to 100 C. for three hours, the pyridine removed and the residue distilled at 3-8 mm. Hg pressure to give 148.0 g. 3-(2'- acetoxyethyl)-2,4-oxazolidinedione, B.P .144 C., which analyzed 7.8% nitrogen (theory: 7.5%).

This acetate was added to a tube packed with stainless steel helices which was heated to 580 C. The pyrolyzate was distilled to give 51.1 g. 3-vinyl-2,4-oxazolidinedione, B.P. 100-105 C./0.2 mm., which analyzed 10.8% nitrogen (theory: 10.8%).

A mixture of 17.0 g. of 0,0-dimethyl phosphorodithioic acid and 8.4 g. 3-vinyl-2,4-oxazolidinedione was heated at 90 C. for 8 hours. The product was dissolved in benzene, washed with aqueous sodium bicarbonate and water and dried. On removal of the benzene, there remained 14.2 g. '0,0-dimethy1 S-[1-(2',4-oxazolidinedione-3'-yl)ethyl]phosphorodithionate which was an oil analyzing 10.4% *P. (10.9% P., theory).

EXAMPLE Following the procedure of Example 9, 20.0 g. 0,0- diethyl phosphorodithioic acid was reacted with 9.0 g. 3-vinyl-2,4-oxazolidinedione and 21.9 g. 0,0-diethyl S-[l- (2,4'-oxazolidinedione 3' yl)ethyl]phosphorodithioate which was an oil analyzing 10.6% P. (9.9% P., theory) was obtained.

Each of the compounds of the above examples was made into a concentrate by dissolving 1.5 g. of the toxicant compound in 1 ml. toluene to which was added 1 ml. Tween (trademark for sorbitol monolaurate polyoxyethylene derivative). This concentrate was then dispersed in 150 ml. water to produce a 1% emulsion, and emulsions of lower concentrations were produced by diluting aliquots of this emulsion with the required amount of water.

The emulsions were then tested against various insects, including two-spotted mites, systemically(TSM-S).

Two-spotted mite, systemic Lima bean rooted seedlings (5 to 6 days old) which have been grown under test conditions are removed from the soil, and the roots are placed in culture tubes containing emulsions of the toxicant at various concentrations. After 24 hours, 50-100 two-spotted mites are placed on the leaves of one such seedling. These tests are carried out at 78 F. and 50% relative humidity. The mortality of mites is determined after 6 days.

The results of the testing is set forth in Table 1.

TABLE 1.TOXICITY TO INSECTS OF COMPOUNDS OF THE FORMULA TSM-S R R Y percent/ppm.

H H s 100 10 H H S 100/50 H CH3 S 100/10 H CHa S 40/50 CH3 CH3 S 100/50 CH; CHa S 80/50 H H O 100/50 H H O 100/50 OH: H S 100/50 CH H S 100/50 Tests were also carried out on potted lima bean seedlings in which the toxicants were applied to the roots as aqueous emulsions and to foliage as aqueous emulsions. Further testing by sowing clay granules containing adsorbed toxicant compounds at the rate of /2 pound per acre along with pea seeds or cotton seeds has been found elfective as shown by toxicity of the plants after sprouting to aphids and other sucking insects.

The compounds of this invention are all highly toxic to the two-spotted mite specifically but they are also toxic to other sucking insects such as mites. Their toxicity as contact insecticides is selective and variable with the compounds used. Their common utility is thus that of a systemic insecticide and in addition they have high toxicity to a wide variety of insects such that mixtures of methyl and ethyl esters, for example, are useful as broad spectrum contact insecticides as well as systemic insecticides.

What I claim and desire to protect by Letters Patent is:

1. A systemically active insecticidal compound of the formula in which Y is O or S; R is CH or C H and R and R are CH or H.

2. The compound of claim 1 in which Y is S, R CH and R and R are H.

3. The compound of claim 1 in which Y is S, R C H and R and R are H.

4. The compound of claim 1 in which Y is O, R is CH and R and R are H.

5. The compound of claim 1 in which Y is O, R is C H and R and R are H.

6. The compound of claim 1 in which Y is S, R CH R is CH; and R is 7. The compound of claim 1 in which Y is S, R CH R is H and R is CH References Cited UNITED STATES PATENTS 2,553,770 5/ 1951 Kittleson 260-301 FOREIGN PATENTS 1,093,728 11/1954 France 2-6030l ALTON D. ROLLINS, Primary Examiner U.S. Cl. X.R. 424-200, Dig 8 

